Is this the Weyland-Yutani Corporation Corporate Office?

Have no idea... does not seem to be so advanced as far as a Corporate building in the year 2100+ or very Large as far as how you would view a Global Company.

What relevance does this person have? They look like someone in their 30's is it who has taken over from Weyland?  Is it a Weyland Flash Back?

And will it appear or be referenced in the Movie or Viral Marketing.

so i dont know what this could mean, i think the focus is more on who that person is as opposed to the buildings etc

I did my best with contrast to bring down the glare on the glass in order to try and see inside.

Is this for sure in the promos? or was it a mistake?

Its in the Blessed viral video at the :30 mark.

Could it be a glimpse of someones (Tennessee's?) family hearing the message?

Bit simple but you never know :) 

http://www.alien-covenant.com/news/lots-new-alien-footage-shown-these-alien-covenant-tv-spots-spoilers

Appears its someone who works for the Joblo place that does the Trailers etc

That is exactly what I thought Deep Space.

BigDave, that answers the question. I was pissed at first for being fooled with the image but I would have done the same thing if I was in charge of anything related to the trailers.

Not Weyland-Yutani Corporation's corporate office.

Joblo Headquarters, our universe. Montreal, Quebec.